title: How high frequency trading affects a market index.
abstract: The relationship between a market index and its constituent stocks is complicated. While an index is a weighted average of its constituent stocks, when the investigated time scale is one day or longer the index has been found to have a stronger effect on the stocks than vice versa. We explore how this interaction changes in short time scales using high frequency data. Using a correlation-based analysis approach, we find that in short time scales stocks have a stronger influence on the index. These findings have implications for high frequency trading and suggest that the price of an index should be published on shorter time scales, as close as possible to those of the actual transaction time scale.
authors.affiliation: School of Physics and Astronomy, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel. drorkenett@gmail.com
authors.forename: Dror Y
authors.initials: DY
authors.lastname: Kenett
authors.forename: Eshel
authors.initials: E
authors.lastname: Ben-Jacob
authors.forename: H Eugene
authors.initials: HE
authors.lastname: Stanley
authors.forename: Gitit
authors.initials: G
authors.lastname: Gur-Gershgoren
mesh_terms: D003132:Commerce; D007449:Investments